Answer: According to the book "Roses for Dummies", your containerized roses will benefit from winter burial in cold climates. The best time to do this is when nights start to get consistently frosty. Dig a hole and bury the containers in soil (to insulate the roots from extremes in temperatures). After the ground freezes hard, cover the soil with straw mulch. Gradually remove the mulch and soil as temperatures warm in the spring, and unearth the containers.
For any rose, nitrogen based fertilizers should be withheld approximately 6 wks. before expected frost dates, but continue to water throughout the fall. Allow September blooms to stay on the plants to form "hips". Clean up all dead leaves and spent flowers from the bed, since they can harbor disease. The canes of climbers and ramblers can be wrapped in burlap and secured to some support stakes for extra protection against dessicating winds and heavy snowfall (and in your zone I probably would take that extra step).
In the spring, when buds begin to swell on the canes, prune them back (1/2 to 1/3 of last year's growth) to allow new flowering stems to develop.
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